Screening apparatus



M. P. REYNOLDS.

SCREENING APPARATUS.

APPLICATION FILED APR. I5. 1918.

3, 9, Patnted Mar. 9,1920.

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J 4 I 5 lflilo 0 b l o o 0H1] V )1 D A specification,

UNITED SIATES lth imfil l PUNSHON REYNOLDS, 0F CLEVELAND, OHIO, ASSIGNOBJ T0 VJ. S. TYLER CGMPANY, 01F CLEVELAND, OHI'O, A CURPORATIGN OF OHIO.

SCREENING APPARATUS.

,eis.

Application filed April 15, 19 18.

ltnrxonos. a citizen'o'f the United States,

and a resident of Cleveland, county of Guyahoga, and State 01. Ohio, have invented a new and useful Improvement in Screening Apparatus, of which the following is a the principle oi the invention being herein'explained. and; the best mode in which 1 have contemplated agplying that principle so as to distinguish it from other in veutions.

The present invention, relating, as indicated, to screening apparatus is more par ticularly directed to the provision in apparatus to be used for graduating sanu. ore, stones and the like of means adapted to increase the resilience and the tie oi the screen and hence increase the capacity of the sheen. It has but recently been recognized that the tonnage capacity of a screen depends to a very large extent upon the degree ottension of the screen and upon the uniformity of its tension across the entire surface of the screen cloth. If the screen. is not tensioned to the proper degree, it cannotbe vibrated to any considerable extent. and if the tension is not uniform then the screen will sag and channels will form; down which will flow the greater part of the material, in this Way causing the material to wear out Very fast at these channels.

It customary to vibratev screens by means of bars attached to the screen surface at regular intervals, these bars usually bearing hammerposts. which are intermittently struck. In this way it possible for a single blow to cause the 'VlbltLlYlOll of the screen folits entire length, but i have "Found that the vibration or" the screen is restricted and dampened by the lack of resilience and resistance to movement of the bars attached to the screen for receiving the i blows.

It is obvious that n matter how-tightly tensionml a screen surface may be, it cannot vibrate freely under a blow it it is held back by a non-resilient and relatively inflexible member in the form of a heavy her extending entirely .across the screen and attached to the same at a. number of points. The natural etiect of such a bar is'to dampen the vibrations and to increase very much the resistance of the screen to a bolt. One

importantobject of the present invention Specification 0t Letters Patent.

Serial No. 228.581.

is to provide means that will not only not dampen the vibration of the screen, but will positively assist and increase the vil'nration. To the accomplishment of the foregoing and related ends, said invent-ion, then, consists of the means hereinafter fully described and particularly pointed out in the claims.

The annexed. drawing and the following description set forth in detail certain. mechanism embodying the invention such disclosed means constituting, however, but one of various mechanical forms in Which the principle of the invention may be used.

In said ai'inexed drawiug:

Figure 1 is a plan view of the screen surface, to which is attached a single lon-- gitudinally ektendinp; bar "for carrying the impact posts: Fig. 2 is an end view oi the same; Figs. 25, 4, 5, (3 and 7 are transverse sections of a screen and bar attached thereto taken as on the line oa -0', in Fig. 1, but showing, varioustypes of bars which I have found advantageous for the purpose desired.

In. Fig. l there is shown a woven wire screen cloth 1, attached at either side to metal stripe-2. which it is understood may be attached to suitable members in the framework of a screening machine. The screen is ordinarily tensioned by any suitable means to eltect a lllllffl ll'llhl'id high tension in the screen surface, thus giving the screen great resiliency and ability t vibrate under impact. Extending longitudinally of the screen. surface 1 is an impact bar 3. which is ordinarily riveted or bolted to the screen by means of bolts at a series of spaced points and which is free 'at either end so that this impact har is carried solely by the screen surface and is freely mova- 'hle therewith. Mounted on the impact bar are impact posts 5 of which there may be two or mo for receiving blows in iparted thereto for vibrating the screen.

impact bars for receiving the blows for vibrating the screen have ordinarily been constructed and mounted in the manner shown in Fl 1, but have always been con structed, so far as I am avvare,'o't ordinary strap iron of the usual character which had no resilience in any Way proportional to the resilience oi? the screen. 1'. have found that very remarkable increase in the capacity of a screen to graduate materials can he obtain Patented Mar. s, teen.

ed by proportioning the weight, strength and resilience of these impact bars to the character of the screen and to the character of the material to be graded. The impact bars are first of course proportioned to the type of the screen, itself and are formed of some flexible and resilient material, such as spring steel or tough elastic woods, which will have a resilience and a resistance to movement of a )proximately the same amount as the screen surface upon which they are being used. In the event. that wood is used as a material for the flexible strips it will preferably be fastened to a strip of spring steel. although in some cases it may be used alone. as. for example, in the grad ing of flour or similar fine materials which are dry. and which do not tend to splinter or roughen the wood, as would be the case if wood strips were used with a coarse sharp material, such as many kinds of ores and the like.

In Fig. 3 l have shown impact bars, coir sisting of an upper bar (3 and a lower bar 7, of lighter character than the upper, both of which are bolted to the screen surface by bolts 8. In Fig. 4. I have shown a still lighter lower bar 9 which would be used with a screen cloth of lig ter weight and smaller mesh than the sci-eh cloth which is shown in Fig. Z). In Fig. 5 I have shown a single upper bar 11 bolted to the screen cloth. the bolts 12 being provided with washers or metal lugs 13 for preventing the nuts 14 from working into the screen cloth and pulling through. It, is not essential that the strength of the resilient impact bars be proportional. to the character of the screen cloth, as I have found that a very etlicient action can be. secured by using a relatively light spring strip which will allow the screen cloth to vibrate freely without any appreciable resistance on the part; of the strip, as is the case where soft; iron is used.

In Figs. t' and 7 there are shown wooden strips to and ill disposed above and below a screen cloth l7 and bolted thereto in the manner already described. while in lfiig. T a thin. highly resilient strip of spring steel 18 is interposed between the lower wooden bar lti and the screen surface. it will b. evident that. other combinations of spring steel, resilient wood and other flexible matcrials may be used. depending upon the re ilience and character of the screen surface and the material to he graduated. I

The requirement of all of such combinations of impact bars is that the composite bar, consisting of one or more strips of metal, wood, or other materials. must be flexible and highly resilient and should have approximately the same ability to vibrate and no greater resistance to mo 'ementthan the screen cloth itself.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

1 therefore particularly point. out and dis tiuctly claim as my invention l. Ina screening device, the combination of a uniformly tensioned vibratory woven wire screen. and a vibrating bar mounted across and .in contact with said screen, said bar being highly resilient and being adapted to vibrate said screen when distorted.

2. In a screening device, the combination of a uniformly tensioned vibratory woven wire screen, and a vibratory bar mounted across and in contact with said screen, said bar being of spring steel and being capable of vibrating freely with said screen.

3. In a screening device. the combination of a uniformly tensioned vibratory woven wire screen. and a vibratorv bar mounted on the surface of said screen. and extending thereacross, said bar being of highly resilient material adapting it to vibrate said screen when distorted by means of the resiliency of the bar.

r. In a screening device. the coin. .ration of a uniformly tensioned vibratorv woven wire screen, and a vibratory bar mounted on the surface of said screen, and extending thereacross. said bar being of highly resilicut, material adapting it to absorb the initial shock of a vibratory impulse. and to then transmit the same to all parts of said screen surface.

5. in a screening device. the combination of a uniformly tensioned vibratory woven wire screenpand a vibratory bar mounted on the surface of said screen. and extending thertaicross. said bar being of highly resili ent. material adapting it to be considerably distorted under the initial shock of a vibratory impulse. said bar thereafter being adapted to transmit said impulse throughout. said screen.

Signed by me, this 3rd day of April. 1918.

MORLEY lUNSlIUN REYNOLDS. i 

